Lot
292

AN EXCEPTIONAL COLORED DIAMOND RING

AN EXCEPTIONAL COLORED DIAMOND RING
Set with a round-cornered rectangular-cut fancy vivid blue diamond, weighing approximately 3.43 carats, flanked on either side by a cut-cornered trapeze-cut diamond, mounted in platinumWith report 13287209 dated 1 March 2010 from the Gemological Institute of America stating that the diamond is fancy vivid blue, natural color, VS1 clarity

Accompanied by a supplemental letter dated 25 February 2010 from the Gemological Institute of America stating that the diamond has been determined to be a Type IIb diamond. Type IIb diamonds are very rare in nature (from our experience, less than one half of one percent) and contain small amounts of boron that can give rise to a blue or gray coloration. An unusual property of Type IIb diamonds is that they are semi-conductors and conduct electricity. Historically, the ancient mines of India produced occasional blue diamonds but today the most significant source is limited to the Cullinan (formerly Premier) Mine in South Africa. Among famous gem diamonds, the 70.21 carat Idol's Eye and the 45.52 carat Hope, are examples of Type IIb